【作者】 杨淑霞；

【导师】 郭世明；

【作者基本信息】 西南交通大学 ， 电力电子与电力传动， 2003， 硕士

【摘要】 本文对电动汽车的异步电动机直接转矩控制系统进行了研究，首先从基本原理出发，阐述了适合于电动汽车异步电机的直接转矩控制方案，进行了仿真分析，然后在此基础上，介绍了直接转矩控制的一种优化控制方案，并通过仿真研究验证了这种方法的可行性。 近些年，由于汽车的普及，排放的有害物质直接威胁着人类的健康和赖以生存的环境，70年代三次石油危机又唤起人类对有限石油资源的关注，因此无污染、噪声低的电动汽车又重新受到重视。电动汽车对电驱动系统提出较高的要求，由于直接转矩控制具有控制手段直接、结构简单以及转矩动态响应快等特点，所以将直接转矩控制用于电动汽车驱动系统是可行的。 本文对直接转矩控制的基本原理以及存在的问题作了比较深入的分析。直接转矩控制就是在定子磁场定向的基础上，通过转矩和磁链的闭环控制，实际上就是控制转子磁链和定子磁链的夹角，以获取转矩的高动态响应。本文从基本原理出发，首先给出了一种基于MATLAB／SIMULINK环境下的异步电动机直接转矩控制系统仿真模型。应用该仿真程序，对直接转矩控制系统进行了详细的仿真研究，并分析了传统的直接转矩控制系统的仿真结果。 针对直接转矩控制系统在低速时存在的磁链畸变和转矩脉动等共有的缺点，介绍了优化的控制方案——边带预测优化控制方案，这种控制方案在低速时可以改善定子磁链的波形，可以加快直接转矩控制的动态性能，同时具有计算较为简单，受电机参数影响较小的优点。为了验证这种控制方案的可行性，用MATLAB的SIMULINK进行了仿真研究，通过编写自定义的S-FUNCTION实现复杂的控制算法，仿真结果表明这种方法是可行的，更适合作为电动汽车异步电机驱动系统的控制方案。更多还原

【Abstract】 A systematic and comprehensive research on the Direct Torque Control System of asynchronous motor for Electric Vehicle is introduced in this thesis. The basic mathematical formula of DTC is deduced based on space vector. On the basis of the analysis, an optimization control strategy is introduced and the simulation results show the method is feasible.In recent years, because of environment problem and energy crisis, low pollution and high efficiency vehicles have put more and more eyes on. Electric Vehicles are propelled by electric motors with advantages of no emission, low noise and good efficiency, which have been focused on and stepped into markets. A high efficiency and fast response electric drive system is demanded for EV, and the DTC appears a good future with rapid development of control technology.This thesis describes the construct and the basic working principle of traditional DTC and presents a simulation method for asynchronous motor control system based on MATLAB/SIMULINK. Its simulation program is simple, visual and accurate. Using this program, the performance effect of the Direct Torque Control System is studied in detail. DTC has some drawbacks, e.g. the large torque ripple and flux aberrations are generated, in particular, in a low speed range because of the stator resistance voltage drop of an asynchronous motor.A method, named band width optimization, is introduced to improve the magnetic flux circle when the motor runs at low speed, at the same time, the method can improve the start characteristic of DTC control. The method is simple to be implemented and robust to the variation of the motor parameter. To demonstrate the validity of the method, some experiments with SIMULINK of MATLAB are given, and complex control methods are realized by user-defined S-FUNCTION. The results of computer simulations reveal that the introduced method is feasible and more suitable for EV drive system.更多还原